//The MIT License

//Copyright (c) 2009 Lluis Sanchez, Nick Darnell

//Permission is hereby granted, free of charge, to any person obtaining a copy
//of this software and associated documentation files (the "Software"), to deal
//in the Software without restriction, including without limitation the rights
//to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//copies of the Software, and to permit persons to whom the Software is
//furnished to do so, subject to the following conditions:

//The above copyright notice and this permission notice shall be included in
//all copies or substantial portions of the Software.

//THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//THE SOFTWARE.

using System;
using System.Reflection;
using System.Reflection.Emit;
using Polymorph.Properties;

namespace Polymorph
{
    public abstract class CodeArithmeticOperation : CodeExpression
    {
        protected CodeExpression exp1;
        protected CodeExpression exp2;
        protected Type t1;
        protected Type t2;
        protected string symbol;

        protected CodeArithmeticOperation()
        {
        }

        public CodeArithmeticOperation(CodeExpression exp1, CodeExpression exp2, string symbol)
        {
            this.symbol = symbol;
            this.exp1 = exp1;
            this.exp2 = exp2;

            t1 = exp1.ResultType;
            t2 = exp2.ResultType;

            if (!t1.IsPrimitive || !t2.IsPrimitive || (t1 != t2))
            {
                throw new InvalidOperationException(String.Format(
                    Resources.Operator0CanNotBeAppliedTo1And2,
                    GetType().Name, t1.Name, t2.Name));
            }
        }

        public override void PrintCode(CodeWriter cp)
        {
            exp1.PrintCode(cp);
            cp.Write(" " + symbol + " ");
            exp2.PrintCode(cp);
        }

        public override Type ResultType
        {
            get { return exp1.ResultType; }
        }
    }

    public class CodeAdd : CodeArithmeticOperation
    {
        public CodeAdd(CodeExpression exp1, CodeExpression exp2)
        {
            this.symbol = "+";
            this.exp1 = exp1;
            this.exp2 = exp2;

            t1 = exp1.ResultType;
            t2 = exp2.ResultType;

            if ((!t1.IsPrimitive || !t2.IsPrimitive || (t1 != t2)) &&
                (t1 != typeof(string) || t2 != typeof(string)))
            {
                throw new InvalidOperationException(String.Format(
                    Resources.Operator0CanNotBeAppliedTo1And2,
                    GetType().Name, t1.Name, t2.Name));
            }
        }

        public override void Generate(ILGenerator gen)
        {
            if (exp1.ResultType == typeof(string))
            {
                MethodInfo m = typeof(string).GetMethod("Concat", new Type[] { typeof(string), typeof(string) });
                CodeGenerationHelper.GenerateMethodCall(gen, null, m, exp1, exp2);
            }
            else
            {
                exp1.Generate(gen);
                exp2.Generate(gen);

                //TODO Add checked/unchecked

                if (CodeGenerationHelper.IsUnsignedNumber(t1) && CodeGenerationHelper.IsUnsignedNumber(t2))
                    gen.Emit(OpCodes.Add_Ovf_Un);
                else
                    gen.Emit(OpCodes.Add);
            }
        }
    }

    public class CodeMul : CodeArithmeticOperation
    {
        public CodeMul(CodeExpression exp1, CodeExpression exp2)
            : base(exp1, exp2, "*")
        {
        }

        public override void Generate(ILGenerator gen)
        {
            exp1.Generate(gen);
            exp2.Generate(gen);

            //TODO Add checked/unchecked

            if (CodeGenerationHelper.IsUnsignedNumber(t1) && CodeGenerationHelper.IsUnsignedNumber(t2))
                gen.Emit(OpCodes.Mul_Ovf_Un);
            else
                gen.Emit(OpCodes.Mul);
        }
    }

    public class CodeDiv : CodeArithmeticOperation
    {
        public CodeDiv(CodeExpression exp1, CodeExpression exp2)
            : base(exp1, exp2, "*")
        {
        }

        public override void Generate(ILGenerator gen)
        {
            exp1.Generate(gen);
            exp2.Generate(gen);

            //TODO Add checked/unchecked

            if (CodeGenerationHelper.IsUnsignedNumber(t1) && CodeGenerationHelper.IsUnsignedNumber(t2))
                gen.Emit(OpCodes.Div_Un);
            else
                gen.Emit(OpCodes.Div);
        }
    }

    public class CodeSub : CodeArithmeticOperation
    {
        public CodeSub(CodeExpression exp1, CodeExpression exp2)
            : base(exp1, exp2, "-")
        {
        }

        public override void Generate(ILGenerator gen)
        {
            exp1.Generate(gen);
            exp2.Generate(gen);

            //TODO Add checked/unchecked

            if (CodeGenerationHelper.IsUnsignedNumber(t1) && CodeGenerationHelper.IsUnsignedNumber(t2))
                gen.Emit(OpCodes.Sub_Ovf_Un);
            else
                gen.Emit(OpCodes.Sub);
        }
    }

    public class CodeMod : CodeArithmeticOperation
    {
        public CodeMod(CodeExpression exp1, CodeExpression exp2)
            : base(exp1, exp2, "%")
        {
        }

        public override void Generate(ILGenerator gen)
        {
            exp1.Generate(gen);
            exp2.Generate(gen);

            if (CodeGenerationHelper.IsUnsignedNumber(t1) && CodeGenerationHelper.IsUnsignedNumber(t2))
                gen.Emit(OpCodes.Rem_Un);
            else
                gen.Emit(OpCodes.Rem);
        }
    }
}